For the repair of rubber articles of any type with or without textile or textile-like reinforcement, for example, tire tubes, conveyor belts, inflatable boats, rubber garments, pool animals or rubberized textiles, for example, tent tarpaulins and ground sheets, vehicle tarpaulins and other tarpaulins and the like as well as of plastic articles, so-called "patches" are used which cover the hole- or tear-shaped damage site with a main element which is connected with the area around the site by means of a thin connecting layer which has been applied to the bottom of the main element. When rubber articles have to be repaired, the main element consists of vulcanized rubber and the connecting layer of unvulcanized, vulcanizable rubber which after expert repairs becomes vulcanized. The patches, at least on the bottom, are provided with a cover consisting, for example, of parchment paper or aluminum foil for the protection of the connecting layer, which must be pulled off before the patch is used.
The method of repair is generally known and therefore need only be briefly explained. The damage site must first be cleaned followed by a mechanical or chemical roughening. The area around the damage site is then brushed with an adhesive liquid or paste or vulcanization solution and the patch is then firmly pressed on the damage site, for example, by rolling.
Since the patch according to the invention was developed for the repair of rubber articles, it is described in the following in this respect although it is also suitable for the repair of plastic articles. For these patches, the unvulcanized, vulcanizable connecting layer is supplied with the accelerator required for through vulcanization via the vulcanizing solution brushed on the area around the damage site before the patch is applied while it withdraws the also required sulfur fraction from the article, roughened at the damage site, to be repaired.
Normal type and size damage sites, preferably, utilize commercially available circular, sometimes also rectangular, patches whereby the diameter depends on the size of the damage site. Depending on their diameter, these patches can be used to span larger holes and also smaller tears. Relatively long, often incorrectly called oval, patches with circular ends are used for longer tears but, in part, also strips and tapes are available. It is disadvantageous, however, that different patches having different sizes must be kept on hand for any eventuality in addition to the round patches for the small tears. Sometimes tears have considerable length.
DE-AS 10 08 800 discloses that the sharp edge of the main element gradually ending in one side can be embedded in the projecting edge of the connecting layer in such a way that all around along the entire projecting connecting layer edge, a narrow part of this connecting layer edge overlaps the main element and consequently covers a small part of the surface of the edge of the main element.